/Engine/Plugins/Experimental/MeshModelingToolsetExp/Source/MeshModelingToolsExp/Public/MeshSelectionTool.h
Assign a new unique Polygroup index to the selected triangles
[UFUNCTION](Programming/UnrealArchitecture/Reference/Functions)(CallInEditor, Category=MeshEdits, Meta=(DisplayName="Create Polygroup", DisplayPriority=5)) void CreatePolygroup()